We see a slight performance improvement in our benchmarks from moving to 512 GB from 256 GB. Overall, though, the differences are too small to suggest upgrading for any reason other than needing the additional capacity. And in many cases, the 128 GB version of Crucial's m4 turns out to be faster than the 256 GB model. As a result, we continue to recommend that 128 GB capacity point. Not only is it nice and fast, but it's also large enough to be treated as a system drive, without forcing you to pick and choose your few favorite apps as you'd need to with a 64 GB SSD. Some folks don't mind the inconvenience of constantly bumping up against a relatively low capacity ceiling. For us, there's nothing more aggravating.
Priced just over $200, a 128 GB drive should leave enough room in your budget for a beefy 1 or 2 TB hard drive to store user data. And shoot, if it means stepping down from a Core i7-2600K to a Core i5-2500K for $100 less, we consider that compromise completely worthwhile.
Unfortunately, those decisions aren't commonly available to notebook owners, who often have to choose between SSDs and hard disks as they populate their one and only 2.5" drive bay. The introduction of mSATA should help solve that conundrum, giving power users the option to mix solid-state and conventional storage in the same mobile platform.
SSDs are an expensive commodity. Even though prices continue to drop with the manufacturing advances that affect NAND, you're still looking at a price per gigabyte of at least $1.50. In relation to the history of SSDs, that's pretty impressive. But make a comparison to magnetic storage and you're still sure to get sticker shock. So yeah, hard drives are as much as 30 times less expensive than SSDs. However, in terms of real-world performance, the 64 GB m4 only cuts busy time by a factor of five versus the 500 GB Momentus 5400.6. Clearly, the performance difference doesn't scale linearly with price.
What you can expect from an SSD, though, is that when you spend two times more on a 128 GB drive versus the 64 MB model, you get twice as much space for important apps and files. The corresponding performance increase is icing on the cake. That's not the sort of situation about which we worry. Rather, we want the power user saving up for a 128 GB SSD to know about the performance drop he's experience if he decides 64 GB is enough.
Now, there's nothing wrong with a 64 GB SSD. In a majority of usages, it's going to be significantly faster than a hard drive. Just bear in mind that spending more on the 128 GB model doesn't just get you two times the capacity; you also see a measurable speed-up. That why we're giving our 2011 Recommended Buy award to Crucial's 128 GB m4. This 120/128 GB capacity point continues to be the sweet spot where we believe you're getting the most performance without entirely breaking the bank.